[PATCH] do_acct_process(): don't take tty_mutex

No need to take the global tty_mutex, signal->tty->driver can't go away while we are holding ->siglock. Signed-off-by: Oleg Nesterov <[email protected]> Acked-by: Peter Zijlstra <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
mna · Dec 8, 2006 · 7bcfa95 · 7bcfa95
1 parent 9159350
commit 7bcfa95
Showing 1 changed file with 2 additions and 5 deletions.
diff --git a/kernel/acct.c b/kernel/acct.c
@@ -485,12 +485,9 @@ static void do_acct_process(struct file *file)
 	ac.ac_ppid = current->parent->tgid;
 #endif
 
-	mutex_lock(&tty_mutex);
-	tty = get_current_tty();
-	ac.ac_tty = tty ? old_encode_dev(tty_devnum(tty)) : 0;
-	mutex_unlock(&tty_mutex);
-
 	spin_lock_irq(&current->sighand->siglock);
+	tty = current->signal->tty;
+	ac.ac_tty = tty ? old_encode_dev(tty_devnum(tty)) : 0;
 	ac.ac_utime = encode_comp_t(jiffies_to_AHZ(cputime_to_jiffies(pacct->ac_utime)));
 	ac.ac_stime = encode_comp_t(jiffies_to_AHZ(cputime_to_jiffies(pacct->ac_stime)));
 	ac.ac_flag = pacct->ac_flag;